Program loading works once the actual data path is identified: direct entry stays inside the control, paper tape uses the reader/punch hardware, and a BTR interface substitutes a PC-connected device for the tape reader. Follow the packet—or, on this generation of equipment, follow the characters—from sender to physical connector to controller memory.
Which OKUMA LC20 loading approach fits the hardware?
Three workable approaches are identified. Direct programming requires no external transfer hardware. Paper tape uses the controller’s legacy reader and round parallel-type punch interface. A BTR interface emulates the tape reader while providing a cabled path to a PC.
| Approach | Sender | Physical path | Direction | Best fit | Main constraint |
|---|---|---|---|---|---|
| Program at the control | Operator | Keys and conversational programming | Into controller memory | Create or revise a program without transfer equipment | External backup still needs another path |
| Paper tape | Tape reader or controller punch output | Tape reader for input; round parallel-type punch interface for output | Import and export through separate reader/punch operations | Machine retains functional original tape equipment | Working punches and suitable paper tape can be difficult to obtain |
| BTR interface | PC through the BTR device | Cable and controller tape-reader interface | Both directions | Routine PC transfer on a control lacking a confirmed modern interface | The BTR must match the controller interface and its electrical and data conventions |
RS-232 and floppy hardware are possibilities to inspect, not confirmed LC20 equipment. If either is physically installed, use its documented procedure instead of adding a second transfer path.
Where does the program data stop?
Layer one first. For paper tape, the controller does not receive a network request. A reader turns holes in the tape into electrical character signals and presents them to the controller’s reader input. During export, the controller sends character signals through the round parallel-type punch interface, and the punch records them on tape.
With a BTR interface, the path is PC application to PC-side connection, then BTR electronics, controller tape-reader interface, input function, and controller memory. The controller side sees a simulated tape reader rather than a native PC session. A transfer that never starts can therefore result from a missing cable signal, incompatible interface hardware, an inactive controller input operation, or mismatched PC-side communication settings.
| Path | Addressing | Port or interface | Timing | Settings source |
|---|---|---|---|---|
| Direct entry | None | Controller keyboard | Operator-paced | Controller operating procedure |
| Paper tape input | No network address | Tape-reader input | Reader and controller must exchange characters at a compatible pace | Reader and controller documentation |
| Paper tape output | No network address | Round parallel-type punch interface | Punch must accept the controller’s output pace | Punch and controller documentation |
| BTR transfer | Controller side uses the reader path; PC-side addressing depends on the BTR | BTR cable to reader interface | Match the BTR to the controller handshake and character delivery requirements | BTR label, manual, and controller interface documentation |
What should be checked before selecting a method?
- Inspect the control cabinet and operator area for a tape reader, tape punch connection, BTR device, floppy station, or labeled RS-232 connector. Record connector type and every interface label before buying hardware.
- Trace each cable physically. A connector mounted on the cabinet does not prove that it is wired to the controller or operational.
- Check whether the controller can create and run a short program from its keyboard. This separates a program-entry problem from an external-transfer problem.
- If tape equipment is present, inspect the media path, reader condition, punch condition, and cabling. A failed mechanical reader cannot be corrected with PC communication settings.
- If a BTR is installed, identify its manufacturer and model from its label. Read the required PC-side connection, handshake, character format, and transfer procedure from that device’s documentation.
- Locate the controller operation that reads from the tape-reader path and the operation that sends to the punch path. Button names and sequences must come from the installed control documentation rather than from another OKUMA generation.
Which approach should be recommended?
Use direct conversational programming when the immediate goal is to create one program and the control accepts local entry. It has the shortest path and removes external hardware from the diagnosis. After the program runs correctly, choose an external method for retention.
For recurring PC transfers, select a compatible BTR interface when the machine has a functional tape-reader interface but lacks a verified RS-232 or floppy path. It removes paper handling and supports cable transfer in both directions. Compatibility is decided at the electrical interface and handshake level, not by connector appearance alone.
Keep paper tape as the operating method when the reader, punch, and media are already functional or when preserving the original transfer arrangement matters. Acquiring untested legacy tape equipment solely for routine PC exchange adds mechanical and media failure points.
How is the selected loading path executed?
Direct entry:
- Create the program at the controller, using conversational programming where suitable.
- Review the generated blocks and program structure on the control.
- Run the program under the machine’s normal controlled proving process.
- After successful execution, export it through the installed paper-tape, BTR, or other verified interface for later reuse.
Paper-tape reload:
- Inspect the tape for tears, damaged leader, contamination, and feed problems.
- Load the tape into the reader in the correct direction.
- Place the controller in its documented tape-reader input operation.
- Start the reader and watch for steady tape motion and advancing input activity.
- Confirm that the received program appears in controller memory before removing the tape.
BTR transfer:
- Connect the correctly matched BTR hardware to the controller’s tape-reader interface and connect its PC side as specified by the BTR manufacturer.
- Configure the PC application with the BTR’s required character format, flow control, and transfer mode. Copy the documented values exactly; the LC20 evidence supplies no universal values.
- Prepare the controller’s tape-reader input function so it is ready to accept characters.
- Initiate the transfer according to the BTR sequence and observe activity at the PC, BTR, and controller.
- For backup, invoke the controller’s punch-output operation and capture the outgoing program through the BTR using its documented receive procedure.
How should the transfer be verified?
Separate transport success from program correctness. Activity lights or a completed PC progress bar prove only that part of the path moved data. Confirm that the controller accepted the complete program and stored it under the intended program identity.
| Observation | Likely stopping point | Next check |
|---|---|---|
| No activity anywhere | Controller not ready, PC not sending, or open physical path | Verify operating mode, cable continuity, connector seating, and send sequence |
| PC sends but BTR shows no input | PC-side port or settings | Check the selected port, cable, transfer mode, and BTR-prescribed settings |
| BTR receives but controller stores nothing | BTR-to-reader interface or controller input operation | Check interface compatibility, handshake, wiring, and reader-input selection |
| Program arrives with missing or altered characters | Character format, pacing, handshake, media, or reader condition | Compare the received text with the source and correct the first differing block |
| Program loads but will not execute | Program content rather than transport | Review controller diagnostics, program structure, and unsupported syntax |
For a retained backup, transfer the program out, clear or select a safe alternate memory location according to shop practice, reload the saved copy, and compare its first block, last block, identifiers, and content with the proven version.
FAQ
Can I load an OKUMA LC20 program from a PC?
Yes, when a compatible BTR interface connects the PC to the controller’s tape-reader path. Identify the controller interface and BTR model before configuring the PC-side connection.
Does every OKUMA LC20 have RS-232?
RS-232 is not confirmed as standard equipment here. Inspect the installed hardware and trace any labeled connector to the controller before selecting an RS-232 procedure.
Can I program the OKUMA LC20 without transfer hardware?
Yes. Enter the program at the machine, with conversational programming where applicable, then prove the program before selecting an external backup path.
Does a BTR interface replace the paper-tape reader?
It simulates the tape reader at the controller interface and provides a cabled PC path. The BTR’s electrical interface, handshake, and data format must match the installed controller path.
Can I trust a completed PC transfer message?
No. Verify the program in controller memory, compare its first and last blocks and identifiers with the proven source, then perform the machine’s controlled non-cutting program check as the final verification step.